One example of a shared facility is the coupling facility offered by International Business Machines Corporation. The coupling facility is a shared external storage processor that contains storage accessible by one or more processors coupled to the coupling facility and performs operations requested by the programs in those processors. Data and controls to be shared are stored in storage structures within the coupling facility. In one example, these storage structures include cache, list and/or lock structures.
It is desirable, and sometimes necessary, to reconfigure one or more of the storage structures. For example, it may be desirable or necessary to change the characteristics of a structure or to move the structure from one coupling facility to another coupling facility. If such a reconfiguration is necessary, then it is imperative that it be performed in a manner that is least disruptive for the users of the structure.
Previous attempts have been made to provide capabilities that enable reconfiguration of storage structures of a coupling facility. However, a need still exists for a reconfiguration technique that is minimally disruptive to the users of the structures, is simple from the users' perspective, and is mostly transparent to the users. A further need exists for a capability that facilitates the operation of the reconfiguration, particularly in those sysplexes where there are numerous structures and users of those structures. A need exists for a reconfiguration capability that is controlled by the operating system, rather than the users.